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This set of Hydraulics and Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on Hydraulics And Fluid Mechanics Set 2

Q1 | An object having 10 kg mass weighs 9.81 kg on a spring balance. The value of 'g' at this place is

- 10 m/sec²
- 9.81 m/sec²
- 9.75 m/sec²
- 9 m/sec

Q2 | A flow is called hyper-sonic, if the Mach number is

- Less than unity
- Unity
- Between 1 and 6
- None of these

Q3 | Liquids

- Cannot be compressed
- Occupy definite volume
- Are not affected by change in pressure and temperature
- None of the above

Q4 | When a cylindrical vessel containing liquid is resolved, the surface of the liquid takes the shape of

- A triangle
- A paraboloid
- An ellipse
- None of these

Q5 | Fluid is a substance that

- Cannot be subjected to shear forces
- Always expands until it fills any container
- Has the same shear stress at a point regardless of its motion
- Cannot remain at rest under action of any shear force

Q6 | The force exerted by a moving fluid on an immersed body is directly proportional to the rate of change of momentum due to the presence of the body. This statement is called

- Newton's law of motion
- Newton's law of cooling
- Newton's law of viscosity
- Newton's law of resistance

Q7 | The property of a fluid which enables it to resist tensile stress is known as

- Compressibility
- Surface tension
- Cohesion
- Adhesion

Q8 | The loss of pressure head in case of laminar flow is proportional to

- Velocity
- (Velocity)2
- (Velocity)3
- (Velocity)4

Q9 | The surface tension of mercury at normal temperature compared to that of water is

- More
- Less
- Same
- More or less depending on size of glass tube

Q10 | An air vessel is provided at the summit in a siphon to

- Avoid interruption in the flow
- Increase discharge
- Increase velocity
- Maintain pressure difference

Q11 | The unit of viscosity is

- Metres² per sec
- kg-sec/metre
- Newton-sec per metre²
- Newton-sec per meter

Q12 | Select the correct statement

- Weber's number is the ratio of inertia force to elastic force.
- Weber's number is the ratio of gravity force to surface tension force.
- Weber's number is the ratio of viscous force to pressure force.
- Weber's number is the ratio of inertia force to surface tension force.

Q13 | Choose the wrong statement. Alcohol is used in manometer, because

- Its vapour pressure is low
- It provides suitable meniscus for the inclined tube
- Its density is less
- It provides longer length for a given pressure difference

Q14 | When a tank containing liquid moves with an acceleration in the horizontal direction, then the free surface of the liquid

- Remains horizontal
- Becomes curved
- Falls on the front end
- Falls on the back end

Q15 | A pressure of 25 m of head of water is equal to

- 25 kN/ m²
- 245 kN/ m²
- 2500 kN/m²
- 2.5 kN/ m²

Q16 | The hammer blow in pipes occurs when

- There is excessive leakage in the pipe
- The pipe bursts under high pressure of fluid
- The flow of fluid through the pipe is suddenly brought to rest by closing of the valve
- The flow of fluid through the pipe is gradually brought to rest by closing of the valve

Q17 | The resultant upward pressure of the fluid on an immersed body is called

- Up-thrust
- Buoyancy
- Center of pressure
- All the above are correct

Q18 | When the water level on the downstream side of a weir is above the top surface of a weir, the weir is known as

- Narrow-crested weir
- Broad-crested weir
- Ogee weir
- Submerged weir

Q19 | If the surface of liquid is convex, men

- Cohesion pressure is negligible
- Cohesion pressure is decreased
- Cohesion pressure is increased
- There is no cohesion pressure

Q20 | The atmospheric pressure with rise in altitude decreases

- Linearly
- First slowly and then steeply
- First steeply and then gradually
- Unpredictable

Q21 | Dynamic viscosity of most of the gases with rise in temperature

- Increases
- Decreases
- Remain unaffected
- Unpredictable

Q22 | According to Bernoulli's equation

- Z + p/w + v²/2g = constant
- Z + p/w - v²/2g = constant
- Z - p/w + v²/2g = constant
- Z - p/w - v²/2g = constant

Q23 | Newton's law of viscosity is a relationship between

- Pressure, velocity and temperature
- Shear stress and rate of shear strain
- Shear stress and velocity
- Rate of shear strain and temperature

Q24 | Differential manometer is used to measure

- Pressure in pipes, channels etc.
- Atmospheric pressure
- Very low pressure
- Difference of pressure between two points

Q25 | Non uniform flow occurs when

- The direction and magnitude of the velocity at all points are identical
- The velocity of successive fluid particles, at any point, is the same at successive periods of time
- Velocity, depth, pressure, etc. change from point to point in the fluid flow.
- The fluid particles move in plane or parallel planes and the streamline patterns are identical in each plane